1. Field of the Invention
The present invention relates to an acceleration shock reduction control system for vehicle such as a motorcycle.
2. Description of Background Art
In general, in vehicles such as motorcycles, an acceleration shock often acts on the vehicle at the transition from a decelerating state to an accelerating state. This acceleration shock is caused by an event in which play existing in the drive system of the vehicle, that is, backlash is taken up. For the purpose of avoiding this acceleration shock, the following configuration has been conventionally proposed. More specifically, in this conventional configuration, shock due to backlash and the like at the transition from a decelerating state to an accelerating state is controlled by retarding the ignition timing of the engine, as well as by adjusting the operating time of a fuel-stage returning control. See, for example, Japanese Patent Application Laid-open Publication No. 2004-60528.
However, in the conventional configuration, since the ignition timing is retarded until backlash is taken up after the transition to an accelerating state, it requires time for the backlash to be taken up. In addition, since the ignition timing is gradually returned to normal after the retarding, the acceleration is relatively slow for the throttle opening degree. As a result, although the acceleration shock can be reduced, the engine response seems to be slow in comparison with a state where the above-described control is not performed.